JP2872814B2 - Bearing structure and spindle motor using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor for rotationally driving a recording member such as a magnetic disk and a bearing structure which can be suitably used for the spindle motor.

[0002]

2. Description of the Related Art A spindle motor generally includes a bracket attached to a frame of a driving device, a hub member on which a recording member is mounted, and bearing means interposed between the bracket and the hub member. The bearing means includes a pair of bearing members, and the pair of bearing members are disposed between the bracket and the hub member at a predetermined interval.

[0003]

However, in the conventional spindle motor, since the bearing means is composed of a pair of bearing members, the operation for mounting these bearing members is complicated, and the motor assembling process is complicated. However, there is a problem that the production cost increases.

It is an object of the present invention to provide a novel bearing structure which can be advantageously applied to a spindle motor.

Another object of the present invention is to provide an excellent spindle motor which is relatively simple to manufacture and can maintain a predetermined preload state.

[0006]

In the bearing structure of the present invention, a cylindrical inner sleeve, a pair of short cylindrical outer sleeves disposed outside both ends of the inner sleeve, and both ends of the inner sleeve. parts outer peripheral surface of the pair of outer sleeve
A spherical member interposed between the respective inner peripheral surfaces and a preload applying member interposed between the pair of outer sleeves, wherein the preload applying member has a C-shape in which a part of a ring is cut away.
The outer diameter of be Jo Resona is somewhat smaller set than the outer diameter substantially the same as or which of the pair of the outer sleeve, the pair of outer by selecting one of a plurality of types of applying the preload members having different widths A predetermined preload is applied to the spherical member by being mounted between the sleeves from the outside in the circumferential direction .

In the spindle motor according to the present invention, the bracket, a hub member rotatable relative to the bracket and on which the recording member is mounted, and a hub interposed between the hub member and the bracket. A bearing structure, the bearing structure comprising:
A cylindrical inner sleeve, a pair of short cylindrical outer sleeves disposed outside both ends of the inner sleeve, an outer peripheral surface at both ends of the inner sleeve, and the pair of outer sleeves , respectively;
And a preload applying member interposed between the pair of outer sleeves. The preload applying member has a C-shape in which a part of a ring is cut away. Aliso <br/> outer diameter is somewhat smaller set than the outer diameter substantially the same as or which of the pair of the outer sleeve, the pair of outer sleeves one of a plurality of types of applying the preload members having different widths Lap between
The bearing structure in a preloaded state is formed by mounting from the outside in the direction , the inner sleeve of the bearing structure is fixed to the bracket or the hub member, and the pair of outer sleeves is the hub member or the hub member. Fixed to the bracket.

[0008]

The bearing structure includes an inner sleeve, a pair of outer sleeves, a spherical member and a preload applying member interposed between both ends of the inner sleeve and the pair of outer sleeves, and a unit is formed by these components. Is configured as Therefore, such a structure can be used in place of the conventional two bearing members, and therefore, when applied to a spindle motor, assembling of the motor is facilitated and the number of assembling steps is reduced. Further, the application of preload to the spherical member can be performed by selecting any one of a plurality of types of preload application members having different widths and interposing between the pair of outer sleeves. Can be provided.

Further, the spindle motor includes the bearing structure, wherein an inner sleeve of the bearing structure is fixed to a bracket or a hub member, and a pair of outer sleeves is fixed to the hub member or the bracket. Therefore, the structure of the motor is relatively simple and the assembling work is easy, and the motor can be manufactured more easily than in the past.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a bearing structure according to the present invention and a spindle motor using the same.

First, an embodiment of a bearing structure according to the present invention will be described with reference to FIG. 1 and FIG.

In FIGS. 1 and 2, the illustrated bearing structure 1 includes a hollow cylindrical inner sleeve 2 and a pair of hollow short cylindrical outer sleeves 4 and 6. Annular receiving recesses are provided on the outer peripheral surfaces of both ends of the inner sleeve 2. Further, an annular accommodation recess is provided on the inner peripheral surface of the central portion of the outer sleeves 4 and 6. A plurality of spherical members 8 are movably and rotatably mounted along the recess between the housing recess formed at one end of the inner sleeve 2 and the housing recess of one outer sleeve 4. A plurality of spherical members 10 are movably and rotatably mounted along the recess between the housing recess formed at the other end of the inner sleeve 2 and the housing recess of the other outer sleeve 6. Because of the mounting, the pair of outer sleeves 4 and 6 are disposed at both ends outside the inner sleeve 2, and a gap exists between the pair of outer sleeves 4 and 6. Thus, the preload applying member 12 is interposed.

The preloading member 12 has a ring shape and is partially cut away so as to be inserted between the outer sleeves 4 and 6, and has a C shape as a whole. The outer diameter of the preload applying member 12 is set to be substantially the same as or slightly smaller than the outer diameter of the outer sleeves 4 and 6, so that the bearing structure 1 can be applied to a spindle motor as described later. . A plurality of kinds of such preload applying members 12 having different widths (length in the left-right direction in FIGS. 1 and 2) are manufactured, and one selected from the plurality of kinds is provided between the outer sleeves 4 and 6. Attached to.

The outer ends of the outer sleeves 4 and 6 are provided with annular seals 14 and 16 which can be made of, for example, synthetic rubber, and the inner ends of the outer sleeves 4 and 6 are made of, for example, synthetic resin. Annular seals 18 and 20 that can be formed are mounted. Annular seal 14,
The reference numerals 16, 18, and 20 contact or contact the outer peripheral surface of the inner sleeve 2 to prevent the lubricating grease from scattering to the outside and dust from entering from the outside.

The bearing structure 1 can be assembled, for example, as follows. Referring mainly to FIG. 2, first, one outer sleeve 4 is attached to one end of the inner sleeve 2 (the outer sleeve 4 is provided with a seal 18).
Is fitted in the direction of arrow 22, and a plurality of spherical members 8 are interposed between the two. Next, the other outer sleeve 6 (on which the seal 20 is attached) is fitted to the other end of the inner sleeve 2 in the direction indicated by the arrow 24, and a plurality of outer sleeves 6 are similarly placed between the two. Is interposed. Thereafter, the outer sleeves 4 and 6 are pulled outward, for example, at a preload equivalent pressure, and the distance between the outer sleeves 4 and 6 is measured with the preload applied, and a preload applying member having a width corresponding to the distance is measured. Select 12 and arrow 2
The preload applying member 12 is inserted in the direction indicated by 6. afterwards,
Grease is sealed and seals 14, 16 are attached as required. Thus, the bearing structure 1 as shown in FIG.
Are assembled as a unit, and a preload of a predetermined load is applied to the spherical members 8 and 10 in the assembled state. When the preload applied to the spherical members 8 and 10 is adjusted, as will be easily understood, the preload applying member 12 may be replaced with another member. For example, when the preload is reduced (or increased), the width of the preload is reduced. It may be slightly smaller (or larger).

Next, a spindle motor using the bearing structure 1 will be described with reference to FIG. Third
In the drawing, the illustrated spindle motor 42 includes a bracket 44 and a hub member 46 that is rotatable relative to the bracket 44, and the bearing structure 1 is interposed between the bracket 44 and the hub member 46. Have been. The bracket 44 has a substantially circular bracket body 48, and a flange 50 is integrally formed on an outer peripheral portion of the bracket body 48, and the flange 50 is attached to a frame (not shown) of the driving device. At a substantially central portion of the bracket body 48, a cylindrical wall 5 projecting upward in FIG.
2, one end 56 of the shaft member 54 is fixed to the cylindrical wall 52 by means such as press fitting. This one end 56 has a somewhat larger outer diameter than the other end 58, and a step 60 is defined between them. In the embodiment, the step portion 60 is defined in the shaft member 54, but the step portion (contact surface) is formed by the cylindrical wall 52 of the bracket body 48 without substantially changing the outer diameter of the shaft member 54. It may be specified.

The bearing structure 1 is fixed to the other end of the shaft member 54 by means such as an adhesive, and is positioned at a predetermined position by one end of the inner sleeve 2 abutting on the step portion 60. The hub member 46 formed of a magnetic material is fixed to the pair of outer sleeves 4 and 6 of the bearing structure 1 by means such as press fitting. The hub member 46 has a cylindrical hub body 62 supported by the outer sleeves 4 and 6, and a flange 64 is provided at a lower end of the hub body 62, and an upper surface of the flange 64 is provided with an upper surface such as a magnetic disk. A recording member (not shown) is placed. An annular hanging portion 66 extending downward is provided at a peripheral portion of the flange portion 64, and a rotor magnet 68 is mounted on an inner peripheral surface of the hanging portion 66. A cap member 67 is attached to the upper end of the hub body 62, and the other end is sealed by the cap member 67.

A stator 70 is arranged opposite the rotor magnet 68. The stator 70 includes a stator core 7 formed by stacking a plurality of plates.
2 and a coil 74 wound around the stator core 72, and the stator core 72 is fixed to the cylindrical wall 52 of the bracket body 48. Also, one end 76 of the coil 74
Is led out through a hole 78 formed in the bracket body 48, and the hole 78 is sealed with an adhesive.

In the spindle motor described above, a current is supplied to the coil 74 as required, so that the
The rotor magnet 66 (the hub member 46 and the outer sleeves 4 and 6 of the bearing structure 1, which are integral with the rotor magnet 66) (the bracket 44, the shaft member 54, and the inner sleeve 2 of the bearing structure 1). And a preload applying member 12)
Is rotated in a predetermined direction.

In the spindle motor as described above, the stator 70 and the shaft member 54 are mounted on the bracket 44, while the rotor magnet 68 and the bearing structure 1 are mounted on the hub member 46, and then the bearing is mounted on the shaft member 54. What is necessary is just to mount the inner sleeve 4 of the structure 1, the assembling thereof is easy, and the number of assembling steps is smaller than that in the related art.

Although the embodiments of the bearing structure according to the present invention and the spindle motor to which the same are applied have been described above, the present invention is not limited to such embodiments.
Various changes and modifications can be made without departing from the scope of the present invention.

For example, in the illustrated embodiment, the bearing structure has been described as applied to a fixed shaft type spindle motor. However, the present invention is not limited to this, and is also applicable to a shaft rotating type spindle motor known per se. The same can be applied.
In such a case, the shaft member integral with the hub member is fixed to the inner sleeve of the bearing structure, and the pair of outer sleeves of the bearing structure are fixed to the bracket.

[0023]

The bearing structure of the present invention comprises an inner sleeve,
The unit includes a pair of outer sleeves, a spherical member and a preload applying member interposed between outer peripheral surfaces at both ends of the inner sleeve and respective inner peripheral surfaces of the pair of outer sleeves, and these components constitute a unit. And it can be used in place of the conventional two bearing members, and when applied to a spindle motor, assembling of the motor becomes easy and the number of assembling steps is reduced. Further, the application of preload to the spherical member can be performed by selecting any one of a plurality of types of preload application members having different widths and interposing between the pair of outer sleeves. Can be provided. In addition, the preloading member cuts a part of the ring
And is formed in a C-shape.
It is easier to install between leaves in the circumferential direction.
And there is an advantage that workability is improved.

Further, the spindle motor includes the bearing structure, wherein an inner sleeve of the bearing structure is fixed to a bracket or a hub member, and a pair of outer sleeves is fixed to the hub member or the bracket. Therefore, the structure of the motor is relatively simple and the assembling work is easy, and the motor can be manufactured more easily than in the past.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of a bearing structure according to the present invention.

FIG. 2 is an exploded sectional view showing the bearing structure of FIG. 1;

FIG. 3 is a sectional view of an embodiment of a spindle motor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bearing structure 2 Inner sleeve 4, 6 Outer sleeve 8, 10 Spherical member 12 Preload applying member 42 Spindle motor 44 Bracket 46 Hub member 54 Shaft member 66 Rotor magnet 70 Stator

Claims (2)

(57) [Claims] 1. A cylindrical inner sleeve, a pair of short cylindrical outer sleeves disposed outside both ends of the inner sleeve, an outer peripheral surface at both ends of the inner sleeve, and an inner sleeve of each of the pair of outer sleeves . A spherical member interposed between the outer sleeve and a peripheral surface; and a preload applying member interposed between the pair of outer sleeves, wherein the preload applying member has a part of a ring cut away.
The outer diameter of Resona be had C-shaped is somewhat smaller set than the outer diameter substantially the same as or which of the pair of the outer sleeve, the selected one of the plurality of kinds of applying the preload members having different widths A bearing structure, wherein a predetermined preload is applied to the spherical member by being mounted between a pair of outer sleeves from the outside in the circumferential direction . 2. A bracket comprising: a bracket; a hub member rotatable relative to the bracket and on which a recording member is mounted; and a bearing structure interposed between the hub member and the bracket. In the spindle motor, the bearing structure includes a cylindrical inner sleeve, and a pair of short cylindrical outer sleeves disposed outside both ends of the inner sleeve.
Outer peripheral surfaces of both ends of the inner sleeve and the pair of outer sleeves
A spherical member interposed between the respective inner peripheral surfaces of the respective , and a preload applying member interposed between the pair of outer sleeves,
Wherein the preload applying member has a C-shape in which a part of a ring is cut out.
The outer diameter of be Jo Resona is somewhat smaller set than the outer diameter substantially the same as or which of the pair of the outer sleeve, between one of a plurality of kinds of applying the preload members having different widths of the pair of outer sleeve The bearing structure in a preloaded state is formed by mounting the bearing structure from the outside in the circumferential direction , the inner sleeve of the bearing structure is fixed to the bracket or the hub member, and the pair of outer sleeves is attached to the hub member. Alternatively, the spindle motor is fixed to the bracket.